Relationship of mycorrhizal growth enhancement and plant growth with soil water and texture

Soybean plants were grown in pots with or without vesicular-arbuscular mycorrhizal (VAM) fungi in three soils of low plant-available P content, different texture and different water-holding capacities. Mineral nutrients, except P, were provided in a complete nutrient solution. The biomass of non-VAM plants was positively and fungal colonization negatively correlated with increasingly coarse soil texture. There was no correlation of soil P with host or endophyte growth. Plant growth enhancement was positively correlated with soil water content at — 1.5 MPa. These observations suggest soil water status and the mycorrhizal condition interact in influencing plant growth.